Dorothy McKeegan presented on October 2011 her study: High Expansion Gas-foam: a humane agent for emergency killing of poultry? Dorothy studied Zoology at the University of Glasgow before completing the MSc in Applied Animal Behaviour and Animal Welfare at Edinburgh University.

After gaining her PhD in 1999, she worked at Roslin Institute near Edinburgh, conducting neurophysiological and behavioural research relating to the welfare of poultry. Dorothy was appointed as the BVA Animal Welfare Foundation lecturer at Glasgow in February 2005, and her teaching role involves delivering an integrated teaching programme for animal welfare and ethics across the undergraduate curriculum.

As a member of the Division of Animal Production and Public Health, Dorothy continues to pursue her research interests in avian sensory physiology, pain perception and poultry welfare. In current projects she is investigating avian pain, humane emergency slaughter and the welfare implications of production-related conditions. Dorothy also has an educational research interest in the teaching and assessment of ethical reasoning in veterinary students.

During outbreaks of notifiable diseases in poultry control measures require poultry to be killed on-farm, preferably in their production housing in order to reduce the risk of spreading the disease. The Dutch governments interest in the potential of delivering gas into sheds using high- expansion foam as an acceptable method of emergency killing of poultry is shared by the UK government (Defra). To maximise the benefits of complementary research a collaborative programme of research between the respective project leaders Dr Dorothy McKeegan and Dr Marien Gerritzen

(Livestock Research Wageningen UR, NL) was established. Results and conclusions of this complementary research, as well as practical recommendations based on this research project are presented in this report.

Noam Mohr, representing People for the Ethical Treatment of Animals PETA commented on a document of the US Agency for Animal and Plants Health Inspection APHIS, department of Agriculture, concerning the regulations to establish a voluntary program for the control of low pathogenic avian influenza in commercial poultry.

PETA has a strong opinion about the animal welfare during killing of farm animals. Read their reaction:

“On behalf of People for the Ethical Treatment of Animals (PETA) and our more than 1 million members and supporters, I am writing with regard to Docket No. APHIS 2005 0109. In particular, I ask that the USDA, as part of its government control program for low pathogenic avian influenza (LPAI), include provisions to require or, at a minimum, encourage the use of depopulation methods that provide the least traumatic death possible for birds who are slated to be killed.

The USDA has made efforts to include animal welfare issues in its high pathogenic avian influenza (HPAI) response plan, including permitting only methods approved by the American Veterinary Medical Association and holding discussions with scientists and animal protection organizations, including PETA, to consider the suffering inflicted by various killing strategies.

It is therefore surprising that these same issues are completely absent from the LPAI program. Unlike HPAI, which has not struck the United States in years, LPAI outbreaks are regularly detected. For example, Pennsylvania alone detects 15 to 20 outbreaks per year. Each outbreak typically requires the mass killing of entire flocks of birds, each of which can number in the tens of thousands.

The sheer magnitude of the number of animals involved makes it ethically incumbent upon us to minimize their suffering. While the interim rule makes many references to the international standards set by the World Organization for Animal Health (OIE), it fails to mention that OIE guidelines require that when animals are killed for disease control purposes, methods used should result in immediate death or immediate loss of consciousness lasting until death; when loss of consciousness is not immediate, induction of unconsciousness should be non-aversive and should not cause anxiety, pain, distress or suffering in the animals.

Particularly in light of reports from abroad of burning and burying live animals, methods that shock the conscience and violate the most basic standards of animal welfare, the USDA should take all necessary steps to prevent similar abuses from occurring in the United States.

Recommendations

INERT GASES: In particular, when large numbers of birds are to be killed, we recommend the use of inert gases, such as nitrogen or argon, or inert gas mixed with 30 percent carbon dioxide. Inert gases are completely undetectable to birds and provide the most painless death possible under these circumstances. Particularly in cases where sheds cannot be sealed properly (as is often the case, such as, for example, with laying hens), mobile gassing carts filled with inert gas, which render birds painlessly unconscious before killing them via anoxia, should be considered the method of choice. Birds should be carried to the carts individually and upright in order to avoid causing injury, which could lead to disease transmission from exposure to blood or other bodily fluids.

CARBON DIOXIDE: In the United States, the most common method of mass killing of poultry for disease control is the use of carbon dioxide. Carbon dioxide is extremely aversive at high concentrations and is described by humans as ?piercing, stabbing, painful, or causing the eyes to burn or water.? (Conlee KM and others. 2005. Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats. Laboratory Animals 39: 137?61.) If introduced to the birds at extremely low temperatures, as is common, it can result in death by freezing. Often birds are first rounded up and wrapped in plastic tarp, causing not only extreme fear, but also trampling. Please make every effort to ensure that (1) if carbon dioxide is used, it is pumped directly into sheds without the use of plastic sheeting, a proven method used successfully in the 2004 outbreak of the HPAI in British Columbia; (2) where possible, lower, less aversive levels of carbon dioxide are used to render animals unconscious before they are killed with high concentrations; and (3) measures are taken to prevent birds from freezing to death.

OTHER METHODS: Less humane methods of mass killing of birds should not be considered acceptable, such as cervical dislocation, starvation, bludgeoning, bleeding, maceration (except in the case of newborn chicks), and suffocation, including such common methods of suffocation as burying animals alive, shutting off ventilation in sheds, and smothering birds with firefighting foam. Please do everything in your power to discourage these methods. Avian flu response plans will have an enormous impact on the suffering of many millions of animals. Along with protecting the public, the implementation of methods that minimize the pain and suffering of animals should be an overriding priority and be incorporated into this interim rule. Feel free to contact me with any questions. Thank you very much for your consideration.

Sincerely,

Noam Mohr Farmed Animal Researcher People for the Ethical Treatment of Animal.”

Culling animals is an important instrument in fighting infectious animal diseases. To prevent the spread of infectious diseases, from the viewpoint of animal welfare and to prevent infection of humans through contact, animals are preferably culled in the poultry house. Until now, the only available and generally acceptable method was to use CO2 gas.

For poultry houses with a construction unsuitable for gassing, in the Netherlands probably < 30%, methods are being investigated to depopulate the poultry house with minimum human-animal contact. Using foam to cull the animals is a possible acceptable alternative.

Foam can be used in various densities and using various types of gas as a carrier. High-density foam will kill the animals through suffocation. This method is permitted in the USA but suffocation is objected to in the Netherlands from a viewpoint of animal welfare. Adding CO2 to the foam, if the CO2 is released to a sufficient extent and the foam causes no obstruction to the respiratory system, could be an acceptable alternative. However, no form of scientific research has supported this until now.

From the viewpoint of human safety it is essential to avoid or minimise human-animal contact as much as possible. Foam can be used in a simple way with minimum use of personnel so that any contact with the living animals is very limited. In addition, adding foam and therefore moisture will result in a reduction in the amount of dust. If detergents or disinfectants with a virus destroying working are added this can contribute substantially to reducing the virus pressure.

It can be stated in conclusion that using foam to cull animals can be a major alternative to depopulation through gassing but that the consequences for animal welfare have not yet been fully investigated. The minimum human-animal contact and the possibilities for (partial) decontamination are important motivations for further studies into this method.

However, a number of important conditions must be attached to the use of foam as a method of depopulation:

– The foam must be non-irritating and non-corrosive for animal welfare and human safety reasons

– There must be no negative effects on the environment.

– It must not hinder or render depopulation and culling impossible.

Aspects to be studied:

– What are the effects on animal welfare; rapid unconsciousness; cause of death.

– Which types of foam do not cause irritation and are safe for the environment.

– How quickly is CO2 released from the foam (animal welfare).

– What are the effects on the depopulation process; wait time before the foam has biodegraded; amount of water in the poultry house.

– Is it possible to reduce the virus pressure in the poultry house and on organic material.